Differential Diagnosis

• Differential diagnosis of asthma during pregnancy should include the following:
  • Physiologic hyperventilation of pregnancy
    • 60-70% experience dyspnea (often described as air hunger) during the course of normal pregnancy
    • Usually worse in the sitting position and is not exertional
    • Starts in the 1st or 2nd trimester and peaks in the 2nd trimester, then becomes relatively stable in 3rd trimester
  • Pulmonary embolism
    • pregnancy is a hypercoagulable state, which can increase the risk for thromboembolism especially with additional risk factors like smoking
  • Amniotic fluid embolism
  • Bronchitis or pneumonia
  • Postnasal drip due to allergic rhinitis or sinusitis
  • CHF, cardiomyopathy or PE
  • GERD
  • VCD

Diagnosis

• Pregnant patients with asthma who have not previously been tested for allergies should undergo blood testing for specific IgE antibodies to allergens such as dust mites, cockroaches, mold spores, and pets.
• Skin tests are not generally recommended during pregnancy due to small risk of systemic reactions
• Methacholine challenge is not recommended during pregnancy
• Spirometry
  
  

Treatment

• Approximately a third of asthmatics during pregnancy either worsen, stay the same, or improve, with increased likelihood of worsening if they have severe asthma; asthma reverts to pre-pregnancy level within 3 months post-partum.
• Exacerbations occur most often in 3rd trimester; most commonly due to infection (respiratory or UTI) followed by non-adherence to inhaled steroids

NHLBI NAEPP Guidelines

Appropriate Medications during Pregnancy

Schatz

Greenberger

• Asthma Medications
  • American College of Ob/Gyn - "Budesonide is the preferred inhaled cortiocosteroid for use in pregnancy.”
  • NAEPP - “Inhaled corticosteroids other than budesonide may be continued in patients who were well controlled by these agents prior to pregnancy especially if it was thought that changing formulations may jeopardize control”
  • Omailzumab (B)
    • Administer during pregnancy only if clearly needed. Omalizumab may be secreted in breast milk, and possible harm to the infant is unknown, caution should be exercised when administered to a nursing woman.

• Rhinitis Medications
  • Pseudoephedrine (C, use in 3rd trimester only, if at all, due risk of gastroschisis)
  • Azelastine (C)

• GERD Medications
  • Lansoprazole
  • Esopmeprazole
  • Rabeprozole
  • Cimetidine
  • Ranitidine
  • Famotidine

• Antibiotics
  • Azithromycin
  • Penicillin derivatives (including amox/clav, amp/sulb)
  • Cephalosporins
  • Clindamycin
  • Nitrofurantoin

• Other
  • Allergen immunotherapy
    • Allergen Immunotherapy Practice Parameter 2011: Allergen immunotherapy can be continued but is usually not initiated in the pregnant patient. If pregnancy occurs during the build-up phase and the patient is receiving a dose unlikely to be therapeutic, discontinuation of immunotherapy should be considered.
  • Tri-Valent Inactivated Influenza Vaccine

Placental Steroid Metabolism

• The use of the inhaled steroids beclomethasone, budesonide and fluticasone for asthma treatment during pregnancy does not result in any significant effects on neonatal size at birth
• The placenta metabolizes the synthetic steroids beclomethasone, prednisolone, dexamethasone and betamethasone, but does not metabolize budesonide or fluticasone.

FDA Pregnancy Categories

United States FDA Pharmaceutical Pregnancy Categories
---A---	Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
---B	Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
---C	Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
---D	There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
---X	Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

Asthma During Menarche and Menopause

• Menarche
  • Increased airway hyperreactivity during perimenstrual and periovulatory phases
  • Early menarche associated with increased adult-onset asthma
• Menopause
  • In at least some women, menopausal transition associated with increased adult-onset asthma
  • Menopausal asthma demonstrates increased sputum neutrophils

References